Reversible saw-tooth



(No Model.)

H. J. BOLE.

REVERSIBLE SAW TOOTH.

am Mucous UNITED STATES PATENT OFFICE,

ROBERT OHN BOLE, OF BEAVER FALLS, PENNSYLVANIA.

REVERSIBLE SAW-TOOTH.

SPECIFICATION forming part of Letters Patent No. 374,821, dated December 13,1887.

Applis ation filed June 30, I887. Serial No. 243,004. (No model.)

To aZZ whom, it may concern.-

Be it known that 1, ROBERT JOHN BoLE, a

citizen of the United States, and a resident of Beaver Falls, in the county of Beaver and State of Pennsylvania, have invented certain new and useful Improvements in Reversible Saw-Teeth; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to whichit appertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification, and in which- Figure l is a side view showing a reversible saw-tooth of my improved construction secured in operative position in a saw-blade. Fig. 2 is a side View showing the tooth partly inserted. Fig. 3 is a detail view of the tooth removed. .Fig. 4 is a side view of one of the seats or recesses in which the teeth fit. Fig. 5 is a side view of a modification of my invention. Fig. 6 is a detail View of the modified form of tooth removed, and Fig. 7 is a side view of the recess in which it fits and is secured.

The same letters of reference indicate cor responding parts in all the figures.

Myiuvention consists in a new and improved reversible double-pointed saw-tooth, which will be hereinafter fully described and claimed.

Referring to the several parts by letter, A indicates the blade of the saw, a part only of w hich is here shown, and which is formed with the inclined recesses B, in which the reversible teeth fit and are secured. Each recess is formed with the straight rear side, 0, having the edge beveled from each side, so as to be V-shaped in cross-section, while the inclined bottom D of the recess is formed with a flat level edge, andthe-lower half of the forward side of the recess has a flatedge, while the upper half, F, of the forward side is beveled on both sides of its edge, so as to be V-shaped in cross-section, and also extends in beyond the straight edge of the lower half of the forward side, as shown, the width of the upper half of the recess B being thus somewhat contracted and forming a throat, B.

Gr indicatesmy reversible double-pointed saw-tooth, which is formed with the straight longitudinal rear edge or side having thelongitudinal V-shaped groove H, adapted to fit the beveled rear edge of the recess B, while the bottom and top or upper and lower edges, I

and J, of the tooth are both inclined from the rear edge of the tooth outwardly, the inclined fiat lower edge of the tooth being adapted to fit squarely'down upon, against, the lower inclined fiat edge or bottom, D, of the blade-recess B when the tooth is in its operative position. and forwardly at each end, and is beveled to a point on the inner side of each of itsends at K, and, further, formed with the clearing-recess L between each point and the central forward part of the tooth, it will be seen that each end of the tooth thus forms a cuttingpoint. The central part of the forward edge of the front of the saw-tooth, which lies in line with the points of the two end points of the tooth,is formed with thelongitudinal V-shaped groove M, which is adapted to fit the beveled edge of the upper half of the forward side of the plate-recess B.

In'placing my improved saw-tooth in operative position the tooth is turned slightly,'so as to permit of the lower or inner point of the tooth clearing the upper beveled forward edge,

F, of the recess B, when the tooth is then slid straight down and in, with the rear longitudinal beveled edge, G, fitting in the longitudinal V-shaped groove in the rear edge of the tooth and the forward upper beveled edge,F, fitting in the V-shaped longitudinal groove in the forward central part of the forward edge of the tooth, the tooth being pushed or slid in until the inclined fiat side or edge J of the tooth bears down against the flat inclined bottom of the blade-recess B, as shown in Fig. l of the As the tooth is thus inclined outwardly drawings, when the tooth is secured firmly in position by means of a transverse pin or key, N, which fits in an aperture, 0, one half of which is formed in the central part of the forward grooved edge of the tooth, while the remaining half of thesaid aperture is formed by 5 a semicircular recess in the upper forward beveled edge, F, of the blade-recess, the insertion of this plug or keylocking the tooth firmly in the blade-recess,and the greater part of the pressure upon the tooth when in operation falling upon the long rear side of the recess B, against which the long rear side of the tooth bears.

It will be seen that when the points of my improved double-pointed reversible teeth have become worn through use they can be readily removed by withdrawing the keys N, and can then be reversed and again secured in the saw-blade with the unused points out, thus forming practically a new saw. To assist in removing the teeth from the saw-blades, a small recess, Q, is formed in the lower rear corner of the recess B, as shown, so that after the key Nhas been withdrawn the point of any suitable tool can be introduced into the said recess Q and the tooth thus started,after which it can be readily withdrawn by the hand, as

when driven, or, rather, pushed, into position,-

as it does not act in the least as a wedge.

If desired, I can employ the construction shown in Figs. 5, 6, and 7 without departing in the least from the spirit of my invention. In this construction the recess B in the blade is formed with the straight forward side, A, having the beveled edge V-shaped in crosssection, and the rear side having the lower half of its edge flat, while the upper half'thereof, which extends out forward or in advance of the said lower half, forming the shoulder B, is formed with the beveled edge V-shaped in cross-section, the forward side of the recess B and the rear side, 0 D, thereof being parallel, and the slanting bottom E of the recess, which inclines downward and rearward] y, is flat, with the exception ofa pointed projection, F, of an inverted-V shape, which is formed on the bottom of the recess near the upper forward end thereof. The modified form of tooth shown in the said views, Figs. 5, 6, and 7, is formed with the parallel inclined top and bottom edges, G and H, the said edges being perfectly flat, with the exception of a V-shaped recess, 1, which is cut in each near its rear end, as shown, and the upper half of the rear edge and the lower half ofthe forward edge. The said edges, being parallel, are formed with longitudinal grooves J, V-shaped in cross section, while each point of the tooth is beveled on its under side, and a clearing-recess, K, is formed below the said points, as shown. This modified form of reversible double-pointed tooth can be readily placed in position in the saw-blade, the beveled front and rear edges, 0 and D, fitting in the V-shaped grooves J of the forward and rear edges of the tooth, while, when the tooth has been driven or pushed down to its lowermost point, so that the fiat slanting edge of that end of the tooth bears against the flat bottom of the blade-recess B, the pointed projection F will fit closely up in the V-shaped recess I in that end of the tooth. The toot-h is then locked in position in the blade-recess by means of a plug or key, M, which fits in an aperture, N, one half of which is formed in the forward edge of the recess and the other half in the forward lower edge of the tooth, as shown, each straight side of the tooth being formed with such an aperture, 0, so that when one point of the tooth has become worn through use the tooth can be withdrawn and turned or reversed and placed in the recess with the unused point or end out,

and the recess 1 in that end of the tooth will then fit closelyover the projection F in the bottom of the recess B, and the key is then again inserted, so as to lock the tooth firmly in its operative position.

The points of the teeth can be made a great deal longer by gumming the teeth out under the points.

From the foregoing description, taken in connection with the accompanying drawings, the construction and advantages of myinvention will be readily understood. My improved reversible double-pointed saw-tooth, which may be fastened in position in the blade with either a key-wedge or other suitable fastening, can be removed and reversed as soon as one end or point becomes worn, thus making the saw practically a new one.

It will be seen that, owing to the peculiar form ofthe teeth and the recesses in which they fit, when they are driven or pushed into position in the said recesses of the blade they will not tighten the rim of the saw, which is a. very important feature.

My improved reversible teeth may be used in straight as well as in circular saws.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is

1. The combination, with a saw-blade having the recesses formed each with the parallel beveled rear and forward edges, the forward edge having the reduced flat lower half and the flat inclined bottom, of the herein-described reversible tooth formed with the grooved rear side, the point at each of its ends,

the inclined fiat end edges, and the grooved forward edge lying parallel with the rear grooved edge, substantially as and for the purpose set forth.

2. The combination, with a saw-blade having the recesses formed each with the parallel beveled rear and forward edges, the forward edge having the reduced flat lower portion and the semicircular recess in its beveled edge, and the flat inclined bottom, of the herein-described reversible tooth formed with the grooved rear side, the inclined fiat end edges, the point at each of its ends, the clearing-spaces, and the grooved forward edgelying parallel with the rear grooved edge and having the semicircular recess and the retainingkey, all substantially as and for the purpose herein set forth.

In testimony that I claim the foregoing as my own I have hereunto afiixed my signature in presence of two witnesses.

Witnesses: ROBERT JOHN BOLE.

H. E. FLEMING, G. L. EBERHART. 

